Following neighbors Denmark and Finland, Sweden is among the least corrupt nations in the world.

Sweden fourth on corruption list
The least corrupt country in the world is New Zealand, according to the annual report from independent Transparency International (TI). The second least corrupt is Denmark, Finland is third and Sweden is fourth, just like last year. The most corrupt countries in the world are North Korea and Somalia, both listed at 182. The U.S. ranked 24 on the list.
For more info and the full list:
http://cpi.transparency.org/cpi2011/